Electronics and technology blog    /    Articles    /    Information for beginners

Sometimes it feels like voltage converters are everywhere, even in places where you wouldn't expect to find them. You can find them in power banks, smartphones, TV boxes, computers, USB hubs, routers, and many other devices. But converters are also sold as standalone modules, intended for everything from hobbyist projects to professional use. And today, we're going to talk about these "invisible helpers".

In today’s world, there are many electronic devices, and progress is driving them toward ever-smaller sizes. Repairing them with a “grandpa’s” soldering iron is becoming increasingly difficult, though there are still areas where one can come in handy. But today we’re not talking about soldering irons. We’re looking at much more sophisticated equipment, intended not so much for home use as for professional applications.

I’m often asked about batteries, building battery packs, and where to buy cells without ending up with junk. Today I have a short article and video on the subject.

With the widespread use of various mobile devices—and, consequently, power supplies and power banks—that use a standard USB connector, an entire class of electronic loads designed to test them has emerged. In fact, these loads have a lot in common with regular electronic loads, but their specific applications mean they may have features that regular loads lack. At the same time, they may not be able to do everything their “big brothers” can.

I’m often asked about various things, and questions about changing a power supply’s output voltage are probably among the most common. Today I’d like to explain the subject a little; hopefully it will help someone.

For quite a long time, the simplest solutions were used to test, for example, a power supply under load—powerful resistors or light bulbs. But with the widespread availability of high-power semiconductor components and the emergence of equally powerful power supplies, it became possible to make the process more convenient by using an electronic load.

About 4 years ago, I wrote an article about repairing an air conditioner circuit board. Now someone got in touch with me who had exactly the same board and exactly the same fault. At first, we were talking about the ins and outs of service centers, but one thing led to another, and the conversation turned to whether I could repair the board. Well, why not? I could, so I got it and here’s my report.

Today’s article isn’t just for the sake of it—it’s about a specific topic, as they say. I’ll be discussing one mistake that, for some reason, crops up all too often. And it’s not just beginners who make it; even quite experienced engineers do. Let me say right away: I didn’t write this post to hate on anyone, but rather for the sake of safety. And believe me, I have my reasons.

As it happens, radio amateurs most often use three basic instruments: a voltmeter, an ammeter, and an ohmmeter. But sometimes a job calls for a more complex and less common instrument: an LCR meter. Of course, these instruments come in both professional and "hobbyist" versions, but first, let's look at what an LCR meter actually is.

Today I have a short review on a very popular topic: fuses. Yes, we’re talking about the component that, as everyone knows, is the last thing to blow. Of course, there are plenty of nuances here, and I’ll try to explain some of them.

The other day, someone brought me a power supply to repair. Well, not exactly for repair: it had already been repaired and was working, but according to the person who brought it in, it was behaving strangely. The result was a little unexpected, and that’s what I wanted to tell you about today, since I think anyone could run into this “quirk.”

Today’s article is about repairing—or perhaps restoring—two power supplies from a mini PBX. These units are quite unusual and use some rather unconventional circuit designs, so this will be a long and fairly detailed article. I hope it will be useful for beginners and interesting for experienced repair technicians as well.

These days, it’s not just how long you can run on a standalone power source that matters, but also how quickly you can recharge it. People often complain in the comments that their batteries—lead-acid or lithium—charge slowly, but don’t understand how to speed things up using “legitimate methods.” Today I’ll try to explain why this happens and what you can do about it.

Among hobbyists—and professionals, for that matter—so-called bench power supplies are very popular. Most are essentially universal adjustable voltage and current sources. Some offer extra features in addition to the usual controls, such as trigger-based overload protection, mode memory, or remote control from a PC or smartphone. But in any case, they’re still adjustable power supplies.

Today I'd like to talk about the characteristics of different types of batteries, focusing on their use in UPSs and, more generally, for long-term off-grid power. I'll try to explain the differences between the various battery types, what situations they're suited to, and some charging-related details.

A common question is which power supply to choose for powering an amplifier, LED lighting, an adjustable converter, and other equally useful devices. Choosing a power supply is an important task, so let's take a look at how they differ and how to choose “the one.”

I came across a faulty power supply and decided to jot down a note about repairing it, and while I was at it, answer a few questions people ask me, using a real example, so to speak.

I’ve mentioned before a circuit that indicates when the load current exceeds a certain threshold. Today I’ll show how to use this circuit to modify a basic voltage converter and turn it into a current regulator.